High refractive index aromatic-based siloxane monofunctional macromonomers

ABSTRACT

Optically transparent, relatively high refractive index polymeric compositions and ophthalmic devices such as intraocular lenses, corneal inlays and contact lenses made therefrom are described herein. The preferred polymeric compositions are produced through the polymerization of one or more aromatic-based siloxane macromonomers or the copolymerization of one or more aromatic-based siloxane macromonomers with one or more non-siloxy aromatic-based monomers, non-aromatic-based hydrophobic monomers or non-aromatic-based hydrophilic monomers.

This application is a divisional of U.S. Application Ser. No. 10/000,137filed Nov. 2, 2001, now U.S. Pat. No. 6,730,767.

FIELD OF THE INVENTION

The present invention relates to macromonomers useful in the manufactureof biocompatible medical devices. More particularly, the presentinvention relates to aromatic-based siloxane monofunctionalmacromonomers capable of polymerization alone or copolymerization withother monomers. Upon polymerization or copolymerization, the subjectmacromonomers form polymeric compositions having desirable physicalcharacteristics and refractive indices useful in the manufacture ofophthalmic devices.

BACKGROUND OF THE INVENTION

Since the 1940's ophthalmic devices in the form of intraocular lens(IOL) implants have been utilized as replacements for diseased ordamaged natural ocular lenses. In most cases, an intraocular lens isimplanted within an eye at the time of surgically removing the diseasedor damaged natural lens, such as for example, in the case of cataracts.For decades, the preferred material for fabricating such intraocularlens implants was poly(methyl methacrylate), which is a rigid, glassypolymer.

Softer, more flexible IOL implants have gained in popularity in morerecent years due to their ability to be compressed, folded, rolled orotherwise deformed. Such softer IOL implants may be deformed prior toinsertion thereof through an incision in the cornea of an eye. Followinginsertion of the IOL in an eye, the IOL returns to its originalpre-deformed shape due to the memory characteristics of the softmaterial. Softer, more flexible IOL implants as just described may beimplanted into an eye through an incision that is much smaller, i.e.,less than 4.0 mm, than that necessary for more rigid IOLs, i.e., 5.5 to7.0 mm. A larger incision is necessary for more rigid IOL implantsbecause the lens must be inserted through an incision in the corneaslightly larger than the diameter of the inflexible IOL optic portion.Accordingly, more rigid IOL implants have become less popular in themarket since larger incisions have been found to be associated with anincreased incidence of postoperative complications, such as inducedastigmatism.

With recent advances in small-incision cataract surgery, increasedemphasis has been placed on developing soft, foldable materials suitablefor use in artificial IOL implants. In general, the materials of currentcommercial IOLs fall into one of three general categories: silicones,hydrophilic acrylics and hydrophobic acrylics.

In general, high water content hydrophilic acrylics or “hydrogels” haverelatively low refractive indices, making them less desirable than othermaterials with respect to minimal incision size. Low refractive indexmaterials require a thicker IOL optic portion to achieve a givenrefractive power. Silicone materials may have a higher refractive indexthan high-water content hydrogels, but tend to unfold explosively afterbeing placed in the eye in a folded position. Explosive unfolding canpotentially damage the corneal endothelium and/or rupture the naturallens capsule and associated zonules. Low glass transition temperaturehydrophobic acrylic materials are desirable because they typically havea high refractive index and unfold more slowly and more controllablythan silicone materials. Unfortunately, low glass transition temperaturehydrophobic acrylic materials, which contain little or no waterinitially, may absorb pockets of water in vivo causing light reflectionsor “glistenings.” Furthermore, it may be difficult to achieve idealfolding and unfolding characteristics due to the temperature sensitivityof some acrylic polymers.

Because of the noted shortcomings of current polymeric materialsavailable for use in the manufacture of ophthalmic implants, there is aneed for stable, biocompatible polymeric materials having desirablephysical characteristics and refractive index.

SUMMARY OF THE INVENTION

Soft, foldable, high refractive index, high elongation polymericcompositions of the present invention are produced through thepolymerization of aromatic-based siloxane macromonomers, either alone orwith other monomers. The subject macromonomers are synthesized through atwo-phase reaction scheme. The polymeric compositions produced from thesiloxane macromonomers so synthesized have ideal physical properties forthe manufacture of ophthalmic devices. The polymeric compositions of thepresent invention are transparent, of relatively high strength fordurability during surgical manipulations, of relatively high elongation,of relatively high refractive index and are biocompatible. The subjectpolymeric compositions are particularly well suited for use asintraocular lens (IOL) implants, contact lenses, keratoprostheses,corneal rings, corneal inlays and the like.

Preferred aromatic-based siloxane macromonomers for use in preparing thepolymeric compositions of present invention have the generalizedstructures represented by Formula 1 and Formula 2 below,

wherein the R groups may be the same or different aromatic-basedsubstituents; R₁ is an aromatic-based substituent or an alkyl; x is anon-negative integer; and y is a natural number.

Accordingly, it is an object of the present invention to providetransparent, polymeric compositions having desirable physicalcharacteristics for the manufacture of ophthalmic devices.

Another object of the present invention is to provide polymericcompositions of relatively high refractive index.

Another object of the present invention is to provide polymericcompositions suitable for use in the manufacture of intraocular lensimplants.

Another object of the present invention is to provide polymericcompositions that are biocompatible.

Still another object of the present invention is to provide polymericcompositions that are economical to produce.

These and other objectives and advantages of the present invention, someof which are specifically described and others that are not, will becomeapparent from the detailed description and claims that follow.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to novel aromatic-based siloxanemacromonomers synthesized through a two-phase reaction scheme. Thesubject aromatic-based siloxane macromonomers are useful in theproduction of biocompatible polymeric compositions. The subjectpolymeric compositions have particularly desirable physical properties.The subject polymeric compositions have a relatively high refractiveindex of approximately 1.45 or greater and a relatively high elongationof approximately 100 percent or greater. Accordingly, the subjectpolymeric compositions are ideal for use in the manufacture ofophthalmic devices. The aromatic-based siloxane macromonomers of thepresent invention are generally represented by the structures of Formula1 and Formula 2 below:

wherein the R groups may be the same or different C₆₋₃₀ aromatic-basedsubstituents such as for example but not limited to

R₁ is a C₆₋₃₀ aromatic-based substituent as defined for R or a C₁₋₄alkyl such as for example but not limited to methyl or propyl; x is anon-negative integer; and y is a natural number.

The aromatic-based siloxane macromonomers of the present invention maybe synthesized through a two-phase reaction scheme. The first phase ofthe two-phase reaction scheme is a co-ring opening polymerization of ahydride functionalized cyclic siloxane with a methacrylate-cappeddisiloxane. The resultant silicone hydride-containing macromonomer isplaced under high vacuum with heat to remove the unreacted siliconehydride cyclics. The second phase of the two-phase reaction schemeconsists of a platinum-catalyzed hydrosilylation of an allylicfunctionalized aromatic with the hydride containing siloxane. Thereaction is monitored for loss of hydride by both infrared (IR) andnuclear magnetic resonance (NMR) spectroscopy. NMR analysis of the finalproduct confirms the molecular structure. In producing the subjectmacromonomers, a thirty percent excess of the starting allylic aromaticwas used and no attempt was made to remove the same following completionof the hydrosilylation. Synthesis of the subject aromatic-based siloxanemacromonomers is described is still greater detail in the examples setforth below. Additionally, specific examples of aromatic-based siloxanemacromonomers of the present invention prepared in accordance with theabove-described two-phase reaction scheme are set forth below in Table1.

TABLE 1 Side Chain (R) Structure Si/O Mole % R.I.pentafluorophenylpropyl

18/7  1.44 phenylpropyl

18/7  1.46 p-methoxyphenylpropyl p-methoxyphenylpropylp-methoxyphenylpropyl p-methoxyphenylpropyl

18/7  13/13  7/18 13/37 1.48 1.50 1.52 1.52 3,4-dimethoxyphenylpropyl

18/7  1.48 2-naphthylpropyl ether 2-naphthylpropyl ether2-naphthylpropyl ether

18/7  13/13 13/37 1.53 1.55 1.57 diphenyldipropyl ether

13/13 1.53 triphenylsilylpropyl

13/13 1.58

The aromatic-based siloxane macromonomers of the present invention maybe polymerized alone or as a copolymer with one or more aromaticnon-siloxy based monomers, non-aromatic-based hydrophilic monomers,non-aromatic-based hydrophobic monomers or a combination thereof, toproduce polymeric compositions of the present invention.

Examples of non-siloxy aromatic-based monomers useful forcopolymerization with one or more aromatic-based siloxane macromonomersof the present invention include for example but are not limited to2-phenyoxyethyl methacrylate, 3,3-diphenylpropyl methacrylate,2-(1-naphthylethyl methacrylate) and 2-(2-naphthylethyl methacrylate)but preferably 2-(1-naphthylethyl methacrylate) for increased refractiveindex.

Examples of non-aromatic-based hydrophilic monomers useful forcopolymerization with one or more aromatic-based siloxane macromonomersof the present invention include for example but are not limited toN,N-dimethylacrylamide and methyl methacrylate, but preferablyN,N-dimethylacrylamide for increased hydrophilicity.

The physical and mechanical properties of copolymers produced fromnaphthyl side-chain siloxane macromonomers [Si(NEM)] with naphthylethylmethacrylate (NEM) and N,N-dimethylacrylamide (DMA) are set forth belowin Table 2.

TABLE 2 Composition R.I. Mod.(g/mm²) Tear(g/mm) Rec. % H₂O [Si(NEM)]/NEM/DMA 100/0/0 1.550 129 2 93 0 80/20/0 1.563 222 27 80 0 80/20/5 741.4 80/20/10 1.556 724 55 64 2.7 80/20/20 1.536 357 31 77 6.5 85/15/01.556 103 14 87 0 85/15/10 1.553 332 32 70 1.7 85/15/20 1.533 289 18 818.4 Commercial 1.43 300 50 81 0 silicone elastomer R.I. = refractiveindex Mod. = modulus Rec. = recovery, which is a measure of the abilityof a material to recover to its original shape when stretched and ismeasured as the percentage of recovery.

Examples of non-aromatic-based hydrophobic monomers useful forcopolymerization with one or more aromatic-based siloxane macromonomersof the present invention include for example but are not limited to2-ethylhexyl methacrylate, 3-methacryloyloxypropyldiphenylmethylsilaneand 2-phenyoxyethyl methacrylate but preferably3-methacryloyloxypropyldiphenylmethylsilane for increased refractiveindex. The physical and mechanical properties of copolymers producedfrom naphthyl side chain siloxane macromonomers [Si(NEM)] with3-methacryloyloxypropyldiphenylmethylsilane (MDPPM) and DMA are setforth below in Table 3.

TABLE 3 Composition R.I. Mod.(g/mm²) Tear(g/mm) Rec. % H₂O [Si(NEM)]/MDPPM/DMA 100/0/0 1.550 129 2 93 0 80/20/0 1.556 145 8 95 0 75/25/01.556 144 12 90 0 70/30/0 1.560 138 17 88 0 70/30/10 1.554 227 31 69 2.970/30/20 1.540 257 44 79 7.5 Commercial 1.43 300 50 81 0 siliconeelastomer R.I. = refractive index Mod. = modulus Rec. = recovery, whichis a measure of the ability of a material to recover to its originalshape when stretched and is measured as the percentage of recovery.

No water, low water having less than 15 percent water contentweight/volume (W/V) and high water “hydrogels” having 15 percent orhigher water content W/V polymeric compositions of the present inventionhaving ideal physical characteristics for ophthalmic device manufactureare described herein. Although the monofunctional siloxane macromonomersof Formula 2 polymerize or copolymerize to form crosslinkedthree-dimensional networks, one or more crosslinking agents may be addedin quantities of preferably less than 10 percent W/V prior topolymerization or copolymerization.

Examples of suitable crosslinking agents include but are not limited todiacrylates and dimethacrylates of triethylene glycol, butyl glycol,hexane-1,6-diol, thio-diethylene glycol, ethylene glycol and neopentylglycol, N,N′-dihydroxyethylene bisacrylamide, diallyl phthalate,triallyl cyanurate, divinylbenzene, ethylene glycol divinyl ether,N,N′-methylenebis-(meth)acrylamide, sulfonated divinylbenzene anddivinylsulfone.

In order to produce polymeric compositions of the present invention fromthe subject monofunctional siloxane macromonomers of Formula 2, one ormore strengthening agents must be used. However, strengthening agentsare not necessary to produce polymeric compositions of the presentinvention from the subject difunctional siloxane macromonomers ofFormula 1. One or more strengthening agents are preferably added inamounts less than approximately 50 percent W/V, but more preferably inamounts less than 25 percent W/V, to the macromonomers of Formula 2prior to polymerization or copolymerization thereof.

Examples of suitable strengthening agents are described in U.S. Pat.Nos. 4,327,203, 4,355,147 and 5,270,418, each incorporated herein in itsentirety by reference. Specific examples, not intended to be limiting,of such strengthening agents include cycloalkyl acrylates andmethacrylates, such as for example tert-butylcyclohexyl methacrylate andisopropylcyclopentyl acrylate.

One or more suitable ultraviolet light absorbers may optionally be usedin quantities typically less than 2 percent W/V in the manufacture ofthe subject polymeric compositions. Examples of such ultraviolet lightabsorbers include for example but are not limited toβ-(4-benzotriazoyl-3-hydroxyphenoxy)ethyl acrylate,4-(2-acryloyloxyethoxy)-2-hydroxybenzophenone,4-methacryloyloxy-2-hydroxybenzophenone,2-(2′-methacryloyloxy-5′-methylphenyl)benzotriazole,2-(2′-hydroxy-5′-methacryloyloxyethylphenyl)-2H-benzotriazole,2-[3′-tert-butyl-2′-hydroxy-5′-(3′-methacryloyloxypropyl)phenyl]-5-chlorobenzotriazole,2-[3′-tert-butyl-5′-(3″-dimethylvinylsilylpropoxy)-2′-hydroxyphenyl]-5-methoxybenzotriazole,2-(3′-allyl-2′-hydroxy-5′-methylphenyl)benzotriazole,2-[3′-tert-butyl-2′-hydroxy-5′-(3″-methacryloyloxypropoxy)phenyl]-5-methoxybenzotriazoleand2-[3′-tert-butyl-2′-hydroxy-5′-(3″-methacryloyloxypropoxy)phenyl]-5-chlorobenzotriazolewherein β-4-benzotriazoyl-3-hydroxyphenoxy)ethyl acrylate is thepreferred ultraviolet light absorber.

The subject siloxane macromonomers and polymeric compositionsmanufactured therefrom are described in still greater detail in theexamples that follow.

EXAMPLE 1 Synthesis of Macromonomer (Two-Part Synthetic Scheme)

Part A: Methacrylate End-Capped Hydride Functionalized MacromonomerSynthesis

To a 1000 ml round bottom flask under dry nitrogen was added D₄(octamethylcyclotetrasiloxane), D₄H (tetramethylcyclotetrasiloxane) andM₂ (1,3-bis(4-methacryloyloxybutyl)tetramethyldisiloxane (molar ratio ofeach component dependent on desired chain length and mole % hydridesubstitution). Trifluoromethanesulfonic acid (0.25%) was added asinitiator. The reaction mixture was stirred 24 hours with vigorousstirring at room temperature. Sodium bicarbonate was then added and thereaction mixture was again stirred for 24 hours. The resultant solutionwas filtered through a 0.3μ Teflon® (E.I. du Pont de Nemours andCompany, Wilmington, Del.) filter. The filtered solution was vacuumstripped and placed under vacuum (>0.1 mm Hg) at 50° C. to remove theunreacted silicone cyclics. The resulting silicone hydridefunctionalized siloxane was a viscous, dear fluid.

Part B: General Procedure for the Synthesis of the MethacrylateEnd-Capped Aromatic Side-Chain Siloxanes

To a 500 mL round bottom flask equipped with a magnetic stirrer andwater condenser was added the methacrylate end-capped macromonomer(prepared in Part A above), the aromatic functionalized allylic ether,tetramethyldisiloxane platinum complex (2.5 mL of a 10% solution inxylenes), 75 mL of dioxane and 150 mL of anhydrous tetrahydrofuran undera nitrogen blanket. The reaction mixture was heated to 75° C. and thereaction was monitored by IR and ¹H-NMR spectroscopy for loss ofsilicone hydride. The reaction was complete in 4 to 5 hours of reflux.The resulting solution was placed on a rotoevaporator to removetetrahydrofuran and dioxane. The resultant crude product was dilutedwith 300 mL of a 20% methylene chloride in pentane solution and passedthrough a 15 gram column of silica gel using a 50% solution of methylenechloride in pentane as eluant. The collected solution was again placedon the rotoevaporator to remove solvent and the resultant clear oil wasplaced under vacuum (>0.1 mm Hg) at 50° C. for four hours. The resultingaromatic side-chain siloxane was a viscous, clear fluid.

EXAMPLE 2

To 80 parts of a 13/13 [Si(NEM)] macromonomer was added 20 parts ofnaphthylethyl methacrylate and 0.5% of Irgacure™ 819 (Ciba-Geigy, Basel,Switzerland) as the UV photoinitiator and 0.25% of a commercial triazoleUV blocker (Aldrich Chemical Co). The clear solution was sandwichedbetween two silanized glass plates using metal gaskets and exposed to UVradiation for two hours. The resultant films were released and extractedin isopropanol (IPA) for four hours, followed by air-drying and a 30 mmvacuum to remove the IPA. The clear tack-free films possessed a modulusof 222 g/mm², tear strength of 29 g/mm, recovery of 80% and a refractiveindex of 1.563. Commercial grade silicone rubber exhibits a modulus of300 g/mm², a tear of 50 g/mm, recovery of 81% and a refractive index ofonly 1.43.

EXAMPLE 3

To 80 parts of a 13/13 [Si(NEM)] macromonomer was added 20 parts ofmethyl methacrylate and 0.5% of Irgacure™ 819 as the UV photoinitiatorand 0.25% of a commercial triazole UV blocker (Aldrich Chemical Co). Theclear solution was sandwiched between two silanized glass plates usingmetal gaskets and exposed to UV radiation for two hours. The resultantfilms were released and extracted in IPA for four hours, followed byair-drying and a 30 mm vacuum to remove the IPA. The clear tack-freefilms possessed a modulus of 1123 g/mm², a tear strength of 93 g/mm,recovery of 60% and a refractive index of 1.538.

EXAMPLE 4

To 80 parts of a 13/13 [Si(NEM)] macromonomer was added 20 parts ofnaphthylethyl methacrylate, 20 parts of N,N-dimethylacrylamide and 0.5%of Irgacure™ 819 as the UV photoinitiator and 0.25% of a commercialtriazole UV blocker (Aldrich Chemical Co). The clear solution wassandwiched between two silanized glass plates using metal gaskets andexposed to UV radiation for two hours. The resultant films were releasedand extracted in IPA for four hours, followed by air-drying and a 30 mmvacuum to remove the IPA. The resultant film was hydrated at roomtemperature overnight in borate buffered saline. The clear tack-freefilms possessed a modulus of 357 g/mm², a tear strength of 31 g/mm,recovery of 77%, a water content of 6.5% and a refractive index of1.536.

EXAMPLE 5

To 80 parts of a 13113 [Si(NEM)] macromonomer was added 30 parts of3-methacryloyloxypropylmethyldiphenylsilane, 20 parts ofN,N-dimethylacrylamide and 0.5% of Irgacure™ 819 as the UVphotoinitiator and 0.25% of a commercial triazole UV blocker (AldrichChemical Co). The clear solution was sandwiched between two silanizedglass plates using metal gaskets and exposed to UV radiation for twohours. The resultant films were released and extracted in IPA for fourhours, followed by air-drying and a 30 mm vacuum to remove the IPA. Theresultant film was hydrated at room temperature overnight in boratebuffered saline. The dear tack-free films possessed a modulus of 257g/mm², a tear strength of 44 g/mm, recovery of 79%, a water content of7.5% and a refractive index of 1.54.

The polymeric compositions of the present invention are of relativelyhigh refractive index, relatively high elongation and relatively highclarity. The polymeric compositions of the present invention with thedesirable physical properties noted above are particularly useful in themanufacture of ophthalmic devices such as but not limited to relativelythin, foldable intraocular lens (IOL) implants and corneal inlays.

IOLs having relatively thin optic portions are critical in enabling asurgeon to minimize surgical incision size. Keeping the surgicalincision size to a minimum reduces intraoperative trauma andpostoperative complications. A relatively thin IOL optic portion is alsocritical for accommodating certain anatomical locations in the eye suchas the anterior chamber and the ciliary sulcus. IOLs may be placed inthe anterior chamber for increasing visual acuity in either aphakic orphakic eyes, or placed in the ciliary sulcus for increasing visualacuity in phakic eyes.

The high refractive index polymeric compositions of the presentinvention have the flexibility required to allow implants manufacturedfrom the same to be folded or deformed for insertion into an eye throughthe smallest possible surgical incision, i.e., 3.5 mm or smaller. It isunexpected that the subject polymeric compositions could possess theideal physical properties described herein. The ideal physicalproperties of the subject polymeric compositions are unexpected sincehigh refractive index monomers typically lend to polymers that haveincreased crystallinity and deceased clarity, which does not hold truein the case of the subject polymeric compositions.

Ophthalmic devices such as but not limited to IOLs manufactured usingthe polymeric compositions of the present invention can be of any designcapable of being rolled or folded for implantation through a relativelysmall surgical incision, i.e., 3.5 mm or less. For example, ophthalmicdevices such as IOLs typically comprise an optic portion and one or morehaptic portions. The optic portion reflects light onto the retina andthe permanently attached haptic portions hold the optic portion inproper alignment within an eye. The haptic portions may be integrallyformed with the optic portion in a one-piece design or attached bystaking, adhesives or other methods known to those skilled in the art ina multipiece design.

The subject ophthalmic devices, such as for example IOLs, may bemanufactured to have an optic portion and haptic portions made of thesame or differing materials. Preferably, in accordance with the presentinvention, both the optic portion and the haptic portions of the IOLsare made of polymeric compositions of the present invention.Alternatively however, the IOL optic portion and haptic portions may bemanufactured from one or more differing materials and/or one or morediffering formulations of the polymeric compositions of the presentinvention, such as described in U.S. Pat. Nos. 5,217,491 and 5,326,506,each incorporated herein in its entirety by reference.

The siloxane macromonomers of the present invention may be readily curedin cast shapes, as discussed in more detail below, by one or moreconventional methods. Such methods include for example but are notlimited to ultraviolet light polymerization, visible lightpolymerization, microwave polymerization, thermal polymerization, freeradical thermal polymerization or combinations thereof.

Suitable free radical thermal polymerization initiators which may beadded to the monomers of the present invention include for example butare not limited to organic peroxides, such as acetyl peroxide, lauroylperoxide, decanoyl peroxide, stearoyl peroxide, benzoyl peroxide,tert-butyl peroxypivalate, peroxydicarbonate and the like. Preferablysuch an initiator is employed in a concentration of approximately 0.01to 1 percent by weight of the total monomer mixture. Representative UVinitiators include those known in the field such as for example but notlimited to benzoin methyl ether, benzoin ethyl ether, Darocur™ 1173,1164, 2273, 1116, 2959, 3331 (EM Industries), Irgacur™ 651 and 184(Ciba-Geigy, Basel, Switzerland).

Once the particular material or materials are selected for theparticular ophthalmic device of choice, the same is either cast in moldsof the desired shape or cast in the form of rods and lathed or machinedinto disks. If cast in the form of rods and lathed or machined intodisks, the disks are lathed or machined into IOLs, corneal rings or thelike at low temperatures below the glass transition temperature(s) ofthe material(s). The ophthalmic devices, whether molded orlathed/machined, are then cleaned, polished, packaged and sterilized bymethods known to those skilled in the art.

In addition to intraocular lenses, the polymeric compositions of thepresent invention are also suitable for use in the manufacture of otherophthalmic devices such as contact lenses, keratoprostheses, capsularbag extension rings, corneal inlays, corneal rings or like devices.

IOLs manufactured using the unique polymeric compositions of the presentinvention are used as customary in the field of ophthalmology. Forexample, in a surgical procedure, an incision is placed in the cornea ofan eye. Most commonly through the corneal incision the natural lens ofthe eye is removed (aphakic application) such as in the case of acataractous natural lens. An IOL is then inserted into the anteriorchamber, posterior chamber or lens capsule of the eye prior to closingthe incision. However, the subject ophthalmic devices may be used inaccordance with other surgical procedures known to those skilled in thefield of ophthalmology.

While there is shown and described herein macromonomers, polymericcompositions, methods of producing the macromonomers and polymericcompositions, methods of producing ophthalmic devices using thepolymeric compositions and methods of using ophthalmic devicesmanufactured from the polymeric compositions, all in accordance with thepresent invention, it will be manifest to those skilled in the art thatvarious modifications may be made without departing from the spirit andscope of the underlying inventive concept. The present invention islikewise not intended to be limited to particular structures hereinshown and described except insofar as indicated by the scope of theappended claims.

1. A method of producing aromatic-based siloxane macromonomers

wherein the R groups may be the same or different aromatic-basedsubstituents; R₁ is an aromatic-based substituent or an alkyl; x is anon-negative integer; and y is a natural number, comprising:polymerizing a hydride functionalized cyclic siloxane with amethacrylate-capped disiloxane to form a hydride containing siloxane;and hydrosilylizing with a catalyst and an allylic-functionalizedaromatic, said hydride containing siloxane.
 2. The method of claim 1wherein said R groups may be the same or different aromatic-basedsubstituents selected from the group consisting of


3. The method of claim 1 wherein said R₁ groups may be the same ordifferent aromatic-based substituents or alkyl substituents.
 4. Themethod of claim 1 wherein said R₁ groups may be the same or differentC₆₋₃₀ aromatic-based substituents or C₁₋₄ alkyl substituents.